Scientists Have Developed a Non-Addictive Opioid

The drug works by only targeting the site of pain, not the brain.

The number of deaths from opioid overdoses in the United States increased 280 percent from 2002 to 2015, with over 30,000 Americans dying from these drugs in 2015, according to the most recent statistics from the National Institute on Drug Abuse. This number not only accounts for deaths from illicit use, but also from legal prescriptions. Many people take opioids to treat chronic pain or to recover from surgery, and it’s easy for a medical user to become addicted to powerful narcotics such as Oxycontin, Vicodin, and fentanyl. America’s opioid epidemic seems to have become a cultural mainstay, but if forward-looking medical researchers have anything to say about it, things could change soon.

In a study published Friday in the journal Science, these researchers report that they’ve developed an opioid painkiller that’s been proven effective in rats without producing any of the negative side effects associated with conventional opioids: addiction, slowed respiration, and constipation, just to name a few.

Senior researcher Christoph Stein, of the Free University of Berlin, and his colleagues used computer simulations to develop a novel chemical compound, called (±)-N-(3-fluoro-1-phenethylpiperidin-4-yl)-N-phenyl propionamide — NFEPP for short. NFEPP works much like the powerful opioid fentanyl, except it only targets inflamed tissues, bonding to them because of their lower pH.

“We were pleased to find our initial hypotheses confirmed by the experimental results,” he says.

This image shows how NFEPP avoids the side effects common to most opioids by only binding to inflamed, low-pH tissue.

The researchers caused pain and inflammation in rats’ paws, then treated them with varying amounts of fentanyl and NFEPP. They found that both drugs worked, but NFEPP only affected the inflamed paws, whereas fentanyl had a full-body numbing effect. Fentanyl also created the hallmark effects of opioids in the rats: depressed respiration, drug-seeking behavior, and eventually death. But NFEPP did none of these, even in quantities that would be lethal for fentanyl doses.